An S.F. jury on Thursday convicted 80-year-old Mark Stanley Personette of first-degree murder in the 1978 killing of 15-year-old Marissa Rolf Harvey. Harvey vanished while visiting family and was found the next day in Sutro Heights Park; jurors delivered the verdict after prosecutors laid out decades of evolving forensic evidence.
Case details
Authorities say Harvey disappeared on March 27, 1978, after being dropped off in Golden Gate Park to go horseback riding, and that surfers discovered her body on March 28 in the underbrush of Sutro Heights Park. The coroner reported she had been badly beaten and strangled with a cordlike device. Investigators list the matter under Case ID 782312915, according to the San Francisco Police Department.
How investigators linked Personette
Early-2000s DNA testing produced a male profile on the victim’s sweater, jeans, and a piece of dried gum, but the case went cold until SFPD reopened it and used investigative genealogy to home in on a suspect. According to the San Francisco Chronicle, FBI surveillance in Colorado later recovered trash containing only personal hygiene items with Personette’s DNA, and a subsequent search warrant turned up 1970s maps of San Francisco and a set of California plates with a 1979 sticker — items prosecutors say helped tie him to the scene.
Trial testimony and verdict
Jurors heard from a woman who said Personette raped her in 1979 when she was 16, along with detailed DNA and other physical evidence, before returning a guilty verdict. “After nearly half a century, this verdict brought long-overdue justice for 15-year-old Marissa Harvey,” Assistant District Attorney Katherine Wells said, according to the San Francisco Chronicle.
Sentencing and what's next
Personette — arrested in December 2021 in Colorado — remains in custody and is scheduled to be sentenced on Dec. 17, when a judge will decide his punishment; prosecutors say the outcome could include life behind bars. District Attorney Brooke Jenkins thanked the victim’s family and the survivor and called the verdict accountability for a brutal crime, as reported by CBS Bay Area.
Why the conviction matters
Prosecutors and law enforcement say the case underscores how cold-case units and genetic genealogy are reshaping long-stalled homicide investigations. San Francisco police note the file was reopened in October 2020 and that sustained investigative work ultimately produced the DNA link that led to Personette, per the San Francisco Police Department.
Legal implications
Personette was convicted of first-degree murder and faces sentencing in mid-December; under California law, the judge determines the precise term, which prosecutors say could include life in prison. Defense counsel has said the defense maintains there was reasonable doubt but will respect the jury’s verdict, per reporting from CBS Bay Area.
